A mobile computing device such as a combination handheld computer and mobile telephone or smart phone generally may provide voice and data communications functionality, as well as computing and processing capabilities. For voice and data communications, the mobile computing device typically employs a radio transmitter/receiver (“transceiver”) and one or more antennas. Antenna design for a mobile computing device is an important consideration and is often limited by strict performance constraints.
FIGS. 1A and 1B illustrate two conventional internal antenna designs for a mobile computing device 100. As shown, the mobile computing device 100 comprises an external housing 102 and a printed circuit board (PCB) 104. FIG. 1A depicts a planar inverted-F antenna (PIFA) type design with an internal antenna 106 positioned on the PCB 104 at the top of the mobile computing device 100. The PIFA type design generally requires a ground layer underneath the internal antenna 106. FIG. 1B depicts a paper-clip antenna type design with an internal antenna 108 positioned on the PCB 104 at the bottom of the mobile computing device 100. The paper-clip type design generally requires removal of the ground layer underneath the internal antenna 108.
Some antenna placements may be undesirable if they increase the overall size and shape of the device. In addition, some antenna placements may provide reduced or unsatisfactory performance. Some antenna placements even may prevent compliance with certain regulatory requirements for device operation, such as the FCC specific absorption rate (SAR) limit of 1.6 mW/g. Such problems may be further exacerbated for mobile computing devices with smaller form factors. Accordingly, there exists the need for improved internal antenna architectures for a mobile computing device.